Elevator



S. M. HALSTEAD ET AL ELEVATOR Filed March 24, 1928 July 28, 1931.

17V VIA 14702;?

,4 TToP/VE') Patented July 28, 1931" umrsosmras PATENT OFFICE 'STANLEYM. HALSTEAJ), ANTON I. WICKLAND, AND WAYNE C. TUSTIN, OF SAN JOSE,

CALIFORNIA, ASSIGNOR S, BY DIRECT AND MESNE ASSIGNMENTS, TO WAYNE COM-PANY, OF FORT WAYNE, INDIANA, A CORPORATION OF INDIANA ELEVATORApplication filed March 24, 1928. Serial No. 264,845.

This invention relates particularly to that type of elevators now usedinelevating motor vehicles for cleaning, lubricating, and so on. 'It iscommon practice in devices of this {kind to effect the elevation ofareciprocating piston, with the load thereon, by introducing into thecylinder and below the piston a suitable liquid under pressure. Thisliquid is ordinarily supplied from a tank where air pressure is appliedthereto or removed therefrom, or it may be contained within the pistonand cylinder and transferred directly from one to the other as thepiston rises or falls. In either case the movement of the piston iscontrolled by the air pressure, but since air is elastic the closing ofa valve in the air line does not immediately stop the movement of thepiston.

It is the object of the present invention to provide a device of thecharacter indicated wherein the piston is'under complete control of theoperator and may be stopped instantly, thereby eliminating the dangerspresent in those devices where a gradual stopping only can be efi'ected.

It is also an objectof the invention to provide a device of thecharacter indicated wherein the piston is automatically cushioned at theclose of its 11 ward movement thereby eliminatin 'the sudden jarnowexperienced in known evices of this kind.

It is a still further object of the invention to provide a device of thecharacter indicated that will be simple in construction, economical tomanufacture, and highly eflicient in its practical application. 7

With these and various other objects in view, the invention may consistof certain novel features of construction andoperation,

as will be more fully described and particuarly pointed out inthe secification, drawin and claims appende hereto.

- Til the drawings:

Figure 1 is a vertical transverse section 46 through the device, partlyin'elevation.

Figure 2 is an enlarged sectional view of --'the lower piston bearing. IReferring now more particularly to the drawings, we show at 1 avertically positioned cylinder suitably'mounted in a hole communicatingwith in the ground as 2.

At the upper end of this cylinder 18 mounted a packing or stufling boxof the type shown in Figure 2, and in the center of its lower end isformed a passage 3. Concentrically arranged in cylinder 1 andcommunicating with the passage 3 but closed off from the interior of thecylinder, is an upstanding conduit 4 converging somewhat at its upperend as at 5 and provided with a number of orifices in its side wall nearsaid upper end as indicated at 6. Communicating with the passage 3 is apipe 7 extending to any readily accessible position where it is fittedwith a valve 8 and thence back to and the cylinder 1 at any suitablepoint as 9.

Concentrically mounted in cylinder 1 is a vertically movable cylinder orpiston 10 of less diameter than cylinder 1 and extending through packingbox 11. Bearing rings as 12 and 13 are fitted in cylinder 1, bothbearings being provided with passages 14 and also functioning as a stopfor cylinder 10 which is provided with a flange as 15 for this purpose.The upper end of the cylinder 10 car ries any suitable type of head as16. This cylinder is entirely closed except at the bottom where it isprovided with an opening 17 through which the conduit 4 passes, and itis fitted with a packing or stufiing box 18 removably mounted therein asindicated at 18a.

At 19 we show a conduit passing upwardly through the bottom of cylinder1 and through conduit 4 to the upper part of cylinder 10 when in itslowest position. Conduit 19 also extends to any readily accessibleposition, preferably adjacent valve 8, where it is fitted with a valve20, and thence to a source of air pressure not shown.

When the elevator has been constructed and assembled as above set forth,and the pipe 7 and the cylinders 1 and 10 filled with oil, the latter toa suitable level as 21, it is ready for use. With the valve 8 closed thevalve 20 may be opened and air under any desire pressure 10 above the.level of the liquid therein. There 'will be no movement of the cylinder10 at this time because the pressure applied to the liquid bears againstthe closed valve 8, being carried through orifices 6 and pipe 7, butwhen the valve 8 is opened the oil is Even though the air pressureforced into the cylinder 1 and against the bottom of cylinder 10 therebycausing it to rise. Since the liquid is carried in a closed circuitbetween the cylinders 1' and 10 it is merely transferred as desired fromone to the other so that when the valve 8 is again closed the movementof the cylinder 10 is instantly halted, regardless of the air pressureacting thereon. As the cylinder 10 approaches the upper limit of itsmovement, with valve 8 open, the bearing 18 moves over and successivelycloses the orifices 6 thereby gradually cutting off the flow of liquidtherethrough and preventing the flange 15 from contacting with the stop13 with a jar. The movement of the liquid is, of course, reversed whenvalve 20 is opened to permit reduction of the air pressure in cylinder10. be exhausted to atmospheric pressure in cylinder 10 when there is aload on head 16, the downward movement of the cylinder is instantlystopped when valve 8 is closed.

It is to be understood, of course, that while we have particularlyreferred to oil as the liquid used in the device, any suitablenoncompressible liquid may be used. It is to be further understood thatchanges in form, construction and method of assembly and operation maybe made within the scope of the appended claims.

We claim:

1. An elevator comprising a hollow c linder, a second hollow cylindermounted or vertical movement therein and forming a pressure chambertherewith, a valve controlled conduit communicating with said cylindersand extending into and connected to said second cylinder and having anopening therein, a non-compressible fluid filling said conduit andpressure chamber and a portion of said second cylinder to a point abovesaid opening, means mounted on the second cylinder adapted to close saidopening toward the close of its upward movement, means for introducing acompressible fluid into the second cylinder and for exhausting the sametherefrom.

2. An elevator comprising a hollow cylinder, a hollow piston mounted toreciprocate relative thereto and forming a pressure chamber therewith, avalve controlled conduit communicating directly with the piston andcylinder, an incompressible fluid filling said conduit and pressurechamber and a'portion of said piston, and valve controlled means tointroduce a compressible fluid into the piston.

3. An elevator comprising a hollow cylinder, a hollow piston mounted toreciprocate relative thereto, a valve" controlled conduit communicatingdirectly with the piston and cylinder, piston controlled valve means forI sible pressure chamber therewith, a conduit di-- rectly communicatingwith the pressure chamber and opening into the second cylinder,anon-compressible fluid in said conduit and in said pressure chamber,and in the second cylinder, means controlled by the second cylinder toshut off the flow of the fluid into the conduit from the second cylinderas the latter approaches the limit of its upward movement, means. forintroducing a compresfluidinto the second cylinder, and means forcontrolling the exhaust of the compressible fluid from the secondcylinder.

5. In combination with a hollow cylinder and a hollow pistonreciprocable with respect to each other, a non-compressible fluidcircuit including the cylinder and piston interior, means to supply acompressible'fluid to the surface of the non-compressiblefluid in thepiston, means to exhaust the compressible fluid from the piston, andautomatic means carried by said piston and operable by the upwardmovement of the piston to interrupt said circuit as the pistonapproaches the limit of its upward movement.

6. In an elevator, ond hollow cylinder reciprocable with and spaced fromthe first cylinder, a. conduit communicating with the space between thecylinders and with the interior of the second cylinder, anon-compressible fluid in the conduit, in the space between thecylinders, and in the second cylinder, means carried by and controlledby the movement of thesecond cylinder to close said communicationbetween the conduit and the second cylinder as the latter approaches apredetermined position, means to supply a compressible fluid to thesurface of the non-compressible fluid, in the second cylinder, and meansto exhaust said compressible fluid from the second cylinder.

7. In a liftin device, the combination of a cylinder, a ollow pistonreciprocably mounted therein and spaced therefrom, spacing members"disposed between said piston and cylinder, one of said members forminga stop adapted to be engaged by a portion of said piston, fixed meansfor supplying fluid pressure said piston and cylinder for moving saidpiston, additional fixed means fOI 'COIldl1Ct1Hg fluid from said pistonto said cyhnder, and means on said piston cooperata hollow cylinder, asecing with saidadditional fixed means for ar-.

8. In a lifting device, the combination of In said piston cooperatingwith said fixed member for closing communication between said piston andcylinder after a'predetermined movement of said piston.

9. In a lifting device, the combination of a [5 cylinder, a hollowpiston reciprocably mounted therein, fixed means extending through saidcylinder and piston and extending to a point adjacent the'top of saidpiston in inoperative position, a fixed mem- I bar extending intosaidpiston and connected to a member connected to said cylinder, said fixedmember and said last named member being constantly filled with asubstantially incompressible fluid, means for introducing an- 5 otherfluid to said piston formoving said first named fluid from saidpiston-to said cylinder to thereby move said piston, and means on saidpiston cooperating with said fixed member for closing communication be-Y tween said piston and cylinder after a predetermined movement of saidpiston. STANLEY'M. HALSTEAD. I

ANTON I. WICKLAND. WAYNE C. TUSTIN.

